May 28, 2014

Laser Mainsheet Snags

By Doug

This good question comes from one of our German readers: When gybing in medium or stronger winds, I often encounter the problem that the main gets caught around the end of the boom. In regattas it is one of the many reasons for frustration.

There are 3 ways for a Laser main to get caught:

  1. The main gets caught around the transom when jibing. This happens to all of us. In light air, I like to pull the main in as much as possible in front of the ratchet block so there is less slack to get caught, and the boom goes out much easier without having to run through the ratchet. When the wind is higher, a sharp tug when the boom starts to come across usually lifts the mainsheet just enough to clear the transom. If it gets caught, the way the pros free it is by hitting the inside of the main with the tiller extension rather than moving to the back to free it by hand.
  2. As mentioned, the main gets caught around the end of the boom. I've had this occasionally happen and am not sure how to prevent it, so I'm open to suggestions. But one thing is for sure - the only way to fix this is by reaching back and freeing it with one hand. This can be tricky in a breeze.
  3. The main gets caught in the clue boom block. In my 38 years of sailing Lasers, this has only happened to me once and yes, it was at a critical moment in the final race at the Jeju Worlds. Pulling harder only jammed it more, so my best advice when you cannot figure out what's wrong is to stop, go back, and look at the problem. In my case, pulling hard just made things much worse.
Peckover's Law: easy problems happen during easy times. The really difficult problems nail you at the worst possible times.

Update 5/28/14:  I'm putting this back up to the top because we're still getting comments and it appears there is more to discuss.

24 comments:

  1. It seems to me that the sheet only gets caught around the end of the boom after I do a really good "sharp tug" to prevent the sheet from getting caught around the transom. The tug must flick a portion of the loose sheet (between the rear boom block and the traveler block) into the air higher than the end of the boom, so that the boom snags it as it comes across in the gybe.

    I guess the solution is to do a tug that is big enough to stop the sheet falling below the transom corner, but not so sharp that it flicks it higher than the end of the boom. That easier to say than do. I still occasionally have both problems.

    I also used to have the theory that if you are planning to do two gybes very close together, say for tactical reasons when approaching a leeward mark, and the sheet catches on the transom in the first gybe then there is no need to clear it because it will come off in the second gybe. That was until I discovered the hard way that it is quite possible to end up with the sheet wrapped around BOTH transom corners. Ugh!

    And just when I thought I couldn't find a new way to rig a Laser wrong, I discovered just before launching last Friday that I had rigged the outhaul around the end of the boom. No idea how that happened!

    And then just when I thought I couldn't find a new way to screw up a tack, I managed to poke my tiller extension through the strap on the pocket on the front of my PFD during the tack and then tried to hike on the new tack with it still stuck through there. No idea how that happened!

    Ah! The pleasures of Laser sailing!

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  2. The sheet at the end of the boom is my nightmare... because it´s very dificult to free. Last saturday it happened , in +20knots , I tried to gybe again trying to undo... only to have a look at the "deep blue"... . Could a too big tug be the problem ? It would be great to have a "prevention procedure"...

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  3. Yes, asTillerman tells you, when you gybe, you trim in gently as the boom goes over---OK. If you give the sheet a jerk, then it wraps around the end of the boom.

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  4. As Tillerman suggests, I think the main around the end of the boom is a "user error", ie. caused by too vigorous a jerk on the sheet as the boom comes over.

    As for the mainsheet getting caught, I learned the hard way to dispense with a spring hold-up for my ratchet block. The spring is a natural snag for the mainsheet and any of the other control line. Better to use the rubber boot version I think.

    Speaking of snags, weed can be be nasty thing too, not only because it robs you of speed, but it can also affect control in a big breeze. There's nothing like getting to the top mark and attempting a bearaway for the run with a monkeyfist of weed on your rudder and nothing happens! No flow over the foil = no control. It's a real problem getting rid of it because you simply can't get your hand down the leading edge of the foil due to the speed of the water, so you just have to round up and practically stop. Is there a trick to it? How do others do it?

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  5. I dont claim to always get the gybes right, but it seems to me the times I have looped a half hitch around the boom it was due to a combination of gybing with the boom way out and giving too vigorous tug as other say above. I havent had it happen in quite a while and I think it is because I generally sheet in a bit before gybing and I give a smaller jerk just as I feel the sheet go slack.

    And, I laughed in reading about Tillerman's getting his tiller extension stuck in his PFD pocket - I had that happen recently but it was because my PFD is so old and ragged that it has a rip across the front and the tiller extension went inside the rip. I think I need a new one.

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  6. Number one - transom snag, has happened to me heaps over the years. Number 2 - boom snag has also happened a lot, but not as much as one. It has taken me a while to figure this out, but I am now pretty confident I know what I was doing wrong and have fixed up my technique. The good news is that it's the same problem that causes both issues and it involves being lazy. Which, in theory, makes the fix as simple as stoping being so lazy.

    The important thing, imho, to focus on is the mainsheet tension between the transom block and the end of the boom. We often use this bit of mainsheet for upwind trim settings with comments such as "2 blocking", or an amount of distance between the blocks for light wind or heavy wind. For gybing it's all about the tension. You want the mainsheet to be in a straight line between transom and boom. NO SAGGING. This sagging is what causes the main to hook on the transom in a light or medium wind roll gybe.

    Look at this video https://www.youtube.com/watch?v=BR6ec_nPWbw

    See how Jon removes all the sag in the main by sheeting in quite hard just before the boom gybes? When the main begins to cross the boat, the main falls down on to the gunwale (side) of the laser, and not over the transom. If there had been a big sag in the main on the way into the gybe the main would of caught the water and been pushed on the corner of the transom resulting in a classic transom snag. For a light and medium wind roll tack the main should be in half way anyway - have a think about what the roll does to the apparent wind. You will essentially be beam reaching into an out of the gybe. You can see in the video that Jon has it almost in half way, and has to let it all back out again after the gybe.

    A transom snag is less likely in a heavy air gybe. The mainsheet will already be quite tight between transom and boom due to sail pressure, therefore little mainsheet sag exists before the gybe. However, a little sag can cause the dreaded boom snag. In this case, an excess amount of mainsheet between transom and boom can get flicked up in the air when you do the classic "tug the mainsheet" as the boom crosses in an attempt to avoid the transom snag. Again, I usually sheet in a little directly before a heavy air gybe. I have two ways of gybing in these conditions: 1. run hard by the lee, sheet in a few handfuls and bear off a bit more until the boom comes across. 2. broad reach to broad reach - involves having the main in a little bit to its broad reach setting (you need to ease a little when yo initiate the gybe, but not enough to have an excess amount that gets snagged on the transom or boom.) I noticed that the boom snag almost always happened between races when I was tired and doing very lazy "casual" gybes, or towards the end of a long day racing when I was knackered and doing tired lazy gybes.

    Sorry if this is a bit long winded and if I've lost anyone, but focussing on the amount of main between transom and boom directly before a gybe, and a little bit of discipline to avoid lazy traps, has pretty much eliminated my snagging issues.

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    1. ... With 100 practice gybes surely they would go better. Thanks for the tips !!

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  7. I think I might have an age problem too. Or rather a PFD age problem. I have an old bright yellow PFD that I always wear when sailing on my own on the principle that if I ever do fall in the water and get separated from my boat I will be more visible to any rescuer. It has a very convenient pocket on the front that is fastened with a strap. I fear the buckle on the strap may not be holding it tight any more and it came loose while I was sailing and formed a loop. The extension wasn't actually in the pocket; it was through that loop.

    I need a new PFD. And my next PFD will not have a strap on the front pocket!

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  8. Wow! Thanks for all the suggestions, comments and stories. It's always interesting to hear how different people handle and avoid various problems. I didn't know the main sheet was long enough to snag both sides of the transom at the same time and I had no idea I wasn't getting full use of the pockets on my life jacket.

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  9. Thank you all for this fruitfull discussion and suggestions. Thinking carefully about what I did when the boom snags happened, I realize that indeed I tried to "help" the boom across the boat with a tug. Apparantly I overdid it and I need to work on the fine tuning of this movement - together with many other aspects of the gybe!
    Doug, thank you very much for posting my question, I am sure I will have another one quite soon!

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  10. At national regatta in Russia I had that boom snag in about 7m/s. I suppose it was caused with strong tug during the gybe. Than I tried to free it by gybing, made two or three gybes and it didn`t help. I didn`t want to stop so I went all the way to bottom mark, rounded, and freed the mainsheet. I think that reduced my losses. And sheeting in took lots of effort :)

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    1. With more time to think about this, it happens from heavy-air jibs because I remember it not being easy to go back to free my mainsheet around the boom. Until fixed, the sheet cannot be trimmed in or out so it's impressive that you were able to get to the bottom mark!

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  11. As promised, the more I thought about the comments the more it became obvious to me that I am kind of lost and more questions come up!. One "anonymous" writes that the boom snag might happen when you become lazy in the gybes and don't sheert in properly. As I mentioned in my orriginal question to Doug, the snags mainly happen in strong wind. And, having done my winter homework and watched Steve Cockerill's videos, where he suggests to let out the boom and to use your body weight to initiate the gybe, I tried to do this. How does this relate to the "not doing lazy gybes and sheeting in properly".

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    1. Steve is a good friend and a great sailor. I have seen some of his videos but not the one you mention. But I doubt that he would trim his boom out before a gybe in strong wind because (1) that makes the boat less stable and (2) more sheet out means more sheet to get caught somewhere. And very few people use their weight to initiate a gybe in strong winds. So my advice is follow Steve's advice for light-air gybes and sheet in as much as possible for strong-air gybes.

      Having said that, a lazy gybe is probably when you just let the boom cross without doing something with the mainsheet to make sure it does not get caught. In light air, I like to give the main a tug when the boom starts to come across, and in heavy air I sheet in as much as possible first.

      Anything else is a lazy gybe.

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  12. Hi Doug, I've seen the video ute is referring to and also know Steve quite well (he sponsors me!). Anyways, Steve definitely does recommend sheeting out on a windy gybe (by sheet out it usually means 5-10cm) for the sole reason of making the boat unstable. The boat wants to death roll, and so you find that very little rudder is needed to gybe the boat remains stable, more stable than if you try going into a gybe with the boat flat. It's the same when you try and turn on a bike; if you just move the handlebars left, you fall over. First, you naturally need to lean the bike into the turn which is done subconsciously, and the steering follows the heel, which stops the bike toppling. This is what Steve refers to. Ute, I would say you would want to sheet out to initiate the turn, and then working really quickly to pull at least 2 armfuls and a flick as the sail is about to switch sides. This should stop the snag.

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    1. Oooh ... now you've done it. Out comes the references to Frank Bethwaite and the differences in theory, technique and skill level. The wheels are spinning in Doug's head. He's drawing pictures in the air, fully engaged, seeing the wisdom of Steve's approach but not in agreement with it. I see an extension to the post coming on.

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    2. I have seen video and tried that technique in strong wind. When I was easing sheet the boat starts heeling, I bear away, and it feels like I`m thrown to leeward. It`s really hard to sheet in at the same time, while trying to stay on the boat during the gybe. And after the gybe boat is extremely unstable due to big angle between the sail and wind. Usually I ended up with death roll right after the gybe.
      So this technique is fast and feels natural but takes a lot of concentration and coordination to execute.

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    3. I love the Boat Whisperer DVDs. I use Steve's technique of easing the main to instigate the gybe and it works well - the boat is very quick through the manoeuvre. Like Ilya says, the exit needs practice, but once you understand the principles and get used to the feel, it is a quick and stable way to gybe in a breeze.

      Going back to the original question about transom snags, I found this YouTube video last year. I think Paul Goodison also mentions this technique in his book on Laser Sailing. It is a good way of gybing in light airs, and completely eradicates the transom snag.

      Although, after Tillerman's description of getting the sheet snagged on both corners, eradicating it might be a shame...

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  13. It does take a while to perfect but it ensures the rudder isn't fighting the boat and does lead to a very smooth gybe. The main thing is the boat heeling to leeward - if you can acheive is without easing the sail then that's fine, but easing is one way of achieving that. You do end up in the drink the first 25 gybes of this you do though!

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    1. Sorry it should say heel to windward on the second line not heel to leeward

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  14. Also below 8 knots or so, if you can pull the sail across physically, it usually leads to the best gybe, which I think is what Damian is talking about. Basically, you grab the "falls" which run from the back block on the boom to he traveller blocks, and physically pull the sail across, using a little rudder and a little roll. This means it's impossible for the main to snag and leads to minimal course change on the gybe, which is key. Also, if going into the gybe you lean the boat away from youas you reach for the falls and then roll it on top of you, you get an extra pump which really helps. On the exit, you can again physically pump the sail with the falls which gives a really powerful acceleration and gets you right back up to speed. It's what all he pros do in sub 5-8 knots pretty much.

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    1. Yes, Anonymous is right. I should have given a bit more description of the manoeuvre.

      It is just as he/she describes, but I'd add that you gather the two bits of mainsheet between the end of the boom and the transom blocks with your tiller extension and pull them towards you, grabbing them in your sheeting hand to give them the big pull that gets the sail across.

      It takes a bit of getting used to, but once mastered you retain really good speed through the gybe with minimum rudder movement. And no mainsheet snag.

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  15. My apologies for not getting back sooner, Pam I were at a Sunfish Worlds qualifier over the w/e and there was an interesting rules event that I'm sure Pam will be posting. It's actually funny. And there are a bunch of things from this post that I would like to comment on that deserve new posts (jibing, weeds, etc.)

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